Compound Barb Medical Device and Method

ABSTRACT

A compound barb medical device is provided which includes an elongated body having at least one barb formed along the length of the body, the barb defining an inner surface with a first portion disposed at a first orientation relative to a longitudinal axis of the elongated body, and a second portion disposed at a second orientation relative to the longitudinal axis. Optionally, the barb defines a third portion disposed at a third orientation relative to the longitudinal axis. A method for forming a compound barb on a medical device is also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. ProvisionalPatent Application No. 61/029,964, filed Feb. 20, 2008, the entiredisclosure of which is incorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates generally to forming barbs on medicaldevices. In particular, the present disclosure relates to compound barbmedical device and method of forming compound barbs on sutures.

BACKGROUND OF RELATED ART

Barbed sutures are known for use in medical procedures. Theconfiguration of barbs on a barbed suture may be designed to optimizetissue holding for a particular indication.

In some circumstances, a random configuration of barbs on the exteriorsurface of the suture may be preferred to achieve optimal wound closure.However, in other circumstances, where the wound or tissue repair neededis relatively small, a reduced number of barbs may be desired. In stillother circumstances, a bi-directional barbed suture may be desirable topermit passing of the suture through tissue in one direction over aportion of the suture and permit passing of the suture through tissue ina second direction over another portion of the suture.

While various methods of forming barbs on sutures have been proposed,such methods may be difficult or costly to implement. Thus, thereremains room for improvement with respect to barbed sutures and methodsfor making them.

SUMMARY

A compound barb medical device is provided which includes an elongatedbody having at least one barb extending from the elongated body. Thebarb defines an inner surface, the inner surface includes a firstportion disposed at a first orientation relative to a longitudinal axisof the elongated body, a second portion disposed at a second orientationrelative to the longitudinal axis, and a third portion disposed at athird orientation relative to the longitudinal axis.

In some embodiments, at least one of the first, second, or thirdportions of the compound barb is substantially linear. In otherembodiments, at least one of the first, second, or third portions of thecompound barb is substantially non-linear. In certain embodiments,compound barb medical device is a suture.

In one embodiment, the medical device includes an elongate body whereinthe elongate body is a monofilament suture including an outer surface,and the outer surface is in direct contact with tissue, at least onebarb extending from the elongated body and defining an inner surface,the inner surface including a first portion disposed at a firstorientation relative to a longitudinal axis of the elongate body,wherein the first portion is disposed at a first angle from about 0degrees to about 90 degrees relative to the longitudinal axis of theelongate body; and a second portion disposed at a second orientationrelative to the longitudinal axis of the elongate body, wherein thesecond portion is disposed at a second angle from about 0 degree toabout 90 degrees relative to the longitudinal axis of the elongate body.

A method of forming a compound barb on a medical device in accordancewith the present disclosure is provided and includes providing a medicaldevice having a longitudinal axis, applying vibrational energy to acutting element to form a compound barb on at least a portion of themedical device including forming a first cut in the medical device, thefirst cut having a first ratio of cut depth to diameter of the medicaldevice; forming a second cut in the medical device, the second cuthaving a second ratio of cut depth to diameter of the medical device;and optionally forming a third cut in the medical device, the third cuthaving a third ratio of cut depth to diameter of the medical device. Acompound barb medical device formed by said method is also provided.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present disclosure will be described hereinbelow with reference to the figures wherein:

FIG. 1 is a plan view of a barbed suture having compound barbs formed inaccordance with the present disclosure;

FIG. 2 is a plan view of a two way barbed suture having compound barbsformed in accordance with the present disclosure;

FIG. 3 is a plan view of an alternative embodiment of a barbed suturehaving both single angle barbs and compound barbs formed in accordancewith the present disclosure;

FIG. 4A is a plan view of a segment of a barbed suture having compoundbarbs formed in accordance with the present disclosure;

FIG. 4B is a plan view of an alternative embodiment of a segment of abarbed suture having compound barbs formed in accordance with thepresent disclosure;

FIG. 5 is a plan view of a segment of a bi-directional barbed suturehaving compound barbs formed in accordance with the present disclosure;

FIG. 6 is a plan view of an alternative embodiment of a barbed suturehaving compound barbs formed in accordance with the present disclosure;

FIG. 7 is a plan view of an alternative embodiment of a barbed suturehaving compound barbs formed in accordance with the present disclosure;

FIG. 8 is a plan view of a segment of a barbed suture having compoundbarbs and a loop formed at one end in accordance with the presentdisclosure;

FIG. 9 is a schematic view of an embodiment of an apparatus and methodof forming barbs on a medical device in accordance with the presentdisclosure.

FIG. 10 is a plan view of an alternate embodiment of a segment of abarbed device having compound barbs formed in accordance with thepresent disclosure; and

FIG. 11 is a plan view of another embodiment of a segment of a barbeddevice having compound barbs formed in accordance with the presentdisclosure.

DETAILED DESCRIPTION

Referring in detail to the drawings in which like reference numerals areapplied to like elements in the various views, FIG. 1 illustrates amedical device 100 having an elongated body 14 and at least one compoundbarb 12 extending from the elongated body 14. Compound barb 12 definesan inner surface which includes a first portion 12 a disposed at a firstorientation relative to the longitudinal axis of elongated body 14, asecond portion 12 b disposed at a second orientation relative to thelongitudinal axis, and a third portion 12 c disposed at a thirdorientation relative to the longitudinal axis.

Compound barbs 12 include at least one substantially linear portion. Asillustrated in FIG. 1, first, second and third portions 12 a-c aresubstantially linear. It is envisioned that at least one of the portionsmay be substantially non-linear, such as for example, arcuate asdescribed hereinbelow.

As shown in the exemplary embodiment of FIG. 1, compound barbs 12 may beformed projecting from the medical device 100 towards at least one end.In other alternative embodiments, multiple compound barbs may be formedsuch that some of the barbs project toward one end and the remainingbarbs project toward the other end so as to form a bi-directionalmedical device 200 as generally illustrated in FIG. 2. Alternatively, aplurality of axially spaced barbs may be formed in the same or randomconfiguration and at different angles in relation to each other.Optionally, the medical device may include a plurality of barbs spacedat the same or different lengths according to the type of tissue beingmanipulated and/or procedure performed (not shown). In some embodiments,the compound barb medical device incorporates a loop at the proximal endthereof configured to enhance retention of the device in body tissue ata desired position.

In an alternative embodiment, medical device 300 may be formed toinclude a combination of compound barbs 12 and single angle barbs 13 asshown in FIG. 3. In such an embodiment, the compound barbs 12 and singleangle barbs 13 may be formed along the length of the medical device 300in specified or random patterns. Additionally, the medical device 300may be formed such that compound barbs 12 are all oriented in the samedirection toward one end of medical device 300 and the single anglebarbs 13 are all oriented in the same direction toward the other end ofmedical device 300.

Referring to FIG. 4A, compound barbs 12 having first, second and thirdportions 12 a-c are generally formed by cutting into the surface ofelongated body 14. In embodiments, each of the first, second, and thirdportions 12 a-c may be cut at first, second and third angles α, β, and γrelative to longitudinal axes a, b, and c respectively of elongated body14 which are parallel to a central longitudinal axis ‘D’, wherein thesecond angle β is less than the first angle α, and the third angle γ isless than the second angle β. Compound barb 12 may include a firstportion 12 a which is formed by cutting into elongated body 14 at afirst angle α of from about 0 degrees to about 90 degrees relative tolongitudinal axis “a”, in other embodiments, the first angle α rangesfrom about 30 degrees to about 50 degrees relative to longitudinal axis“a”, a second portion 12 b which is formed by cutting into elongatedbody 14 at a second angle β of from about 0 degrees to about 90 degreesrelative to the longitudinal axis “b”, in other embodiments, the secondangle β ranges from about 2 degrees to about 25 degrees relative to thelongitudinal axis “b”, and a third portion 12 c which is formed bycutting into elongated body 14 at a third angle γ of from about 0degrees to about 90 degrees relative to longitudinal axis “c”, in otherembodiments, the third angle γ ranges from about 2 degrees to about 50degrees relative to longitudinal axis “c”.

In other embodiments, a compound barb medical device includes anelongated body which includes first and second portions, the first andsecond portions of the elongated body are at first and second anglesrespective to a longitudinal axis of the elongated body to form at leastone compound barb (not shown). Optionally, the elongated body of thecompound barb medical device may include a third portion at a thirdangle respective to a longitudinal axis of the elongated body.

Referring to FIG. 4B, each of the first, second and third portions 12a′-c′ may be cut at first, second and third angles α′, β′, and γ′relative to the longitudinal axes “a′”, “b′”, and “c′”, respectively, ofelongated body 140, such that angle α′ is greater than angle β′ andangle γ′ is less than angle β′. Compound barb 120 may include a firstportion 120 a which is formed by cutting into elongated body 140 at afirst angle α′ of from about 0 degrees to about 90 degrees relative tolongitudinal axis “a′”, in other embodiments, the first angle α′ rangesfrom about 30 degrees to about 50 degrees relative to longitudinal axis“a′”, a second portion 120 b which is formed by cutting into elongatedbody 140 at a second angle β′ of from about 0 degrees to about 90degrees relative to longitudinal axis “b′”, in other embodiments, asecond angle β′ ranges from about 30 degrees to about 60 degreesrelative to longitudinal axis “b′”, and a third portion 12 c which isformed by cutting into elongated body 140 at a third angle γ′ of fromabout 0 degrees to about 90 degrees relative to longitudinal axis “c′”,in other embodiments, a third angle γ′ ranges from about 25 degrees toabout 50 degrees relative to longitudinal axis “c′”.

An alternate embodiment of a compound barb suture is shown in FIG. 10.The compound barb 620 includes two portions 620 a, 620 b which aredisposed at two angles, α″ and β″ relative to a longitudinal axis of themedical device. More specifically, the compound barb 620 includes afirst portion 620 a formed from the elongate body 610 at a first angleα″, which is from about 0 degrees to about 90 degrees, in embodiments,from about 30 degrees to about 40 degrees, and in further embodiments,from about 31 degrees to about 38 degrees, relative to a longitudinalaxis A-A of the elongate body 610. The second portion 620 b is formedfrom the elongate body 610 at a second angle β″ which is from about 0degrees to about 90 degrees, in embodiments, from about 1 degrees toabout 10 degrees and in further embodiments, from about 1 degree toabout 8 degrees relative to the longitudinal axis A-A of the elongatebody 610.

Another embodiment of a compound barb device is shown in FIG. 11. Anelongate body 700 is shown including a compound barb 720 having a firstlinear portion 720 a, shown at an angle γ″, relative to a longitudinalaxis B-B of the elongate body 700. Extending from the first portion 720a is an arcuate second portion 720 b at a radius r₇. The elongate body700 also includes a compound barb wherein a first portion 740 a isarcuate and a second portion 740 b is linear.

FIG. 5 illustrates compound barb 12 having three portions 12 a-c, asillustrated in FIGS. 4A and 5, and compound barb 120 having threeportions 120 a-c as illustrated in FIGS. 4B and 5, formed such that someof the barbs project toward one end and the remaining barbs projecttoward the other end so as to form a bi-directional medical device 500.In alternative embodiments, compound barbs are formed such that thebarbs projecting toward one end, for example, towards the proximal end,have the same orientation and angles as the barbs projecting towards theother end, for example, towards the distal end.

In some embodiments, the compound barb may include at least one portionwhich is substantially non-linear. In embodiments, the barbs may includeat least one point of inflection which may define a concave portion, aconvex portion, an arcuate portion and combinations thereof. Forexample, at least one of the portions may be cut at a radius relative tothe longitudinal axis of elongated body 240. As shown in FIG. 6,compound barb 220 may include an arcuate second portion 220 b. Thearcuate portion 220 b may be cut at a radius r₁ relative to thelongitudinal axis of elongated body 240.

In alternative embodiments, an optional fourth portion may be cut at afourth radius. In some embodiments, each of the first, second, third andoptional fourth portions 320 a-d may be cut at first, second, third andfourth radii relative to the longitudinal axis of elongated body 340. Asillustrated in FIG. 7, compound barb 320 may include an arcuate firstportion 320 a which extends away from elongated body 340 at a firstradius r₂, an arcuate second portion 320 b which extends from firstportion 320 a at a second radius r₃, an arcuate third portion 320 cwhich extends from second portion 320 b at a third radius r₄, an arcuatefourth portion 320 d which extends from third portion 320 c at a fourthradius r₅.

In other embodiments, a compound barb medical device may include anelongated body having a barb and first, second, and third portions beingcut at first, second, and third angles respective to a longitudinal axisof the elongated body to form the barb.

The medical device in accordance with the present disclosure may beformed of the type selected from the group consisting of monofilamentsutures, braided sutures, multi-filament sutures, surgical fibers,anchors, slit sheets, ribbons, tape, mesh, stent, scaffolds, pledgets,vascular graft and ribbons. In an exemplary embodiment, the medicaldevice is a suture.

The exemplary medical devices illustrated throughout the figures areshown to be elliptical in cross-sectional geometry. However, thecross-sectional geometry of the medical device may be of any suitableshape, for example, round, square, star shaped, octagonal, rectangular,polygonal and flat.

In some embodiments, a loop is formed at the proximal end of thecompound barb medical device which is configured to enhance retention ofthe device in body tissue at a desired position. As illustrated in FIG.8, loop 410 is formed at the proximal end of the compound barb medicaldevice 400. Loop 410 may be fixed at a predetermined location along thelength of the elongated body 440 of the compound barb medical device400. Loop 410 may be configured and dimensioned to be adjustable alongthe length of elongated body 440 (not shown).

In general, a method for forming a compound barb on a medical deviceincludes the steps of providing a medical device having a longitudinalaxis and forming a compound barb along the medical device wherein thecompound barb defines an inner surface which includes at least a firstportion disposed at a first orientation relative to the longitudinalaxis, a second portion disposed at a second orientation relative to thelongitudinal axis, and a third portion disposed at a third orientationrelative to the longitudinal axis. In embodiments, at least one of thefirst, second, and third portions is substantially linear. Inalternative embodiments, at least one of the first, second, and thirdportions is substantially non-linear or arcuate.

In embodiments, a method of forming a compound barb on a medical deviceincludes forming a first cut in the medical device, the first cut havinga first ratio of cut depth to diameter of the medical device; forming asecond cut in the medical device, the second cut having a second ratioof cut depth to diameter of the medical device; and forming a third cutin the medical device, the third cut having a third ratio of cut depthto diameter of the medical device.

FIG. 9 illustrates an embodiment of an apparatus and method of formingcompound barbs in accordance with the present disclosure. The method isdescribed, for example in U.S. Patent Application No. 60/994,173 filedSep. 17, 2007 and titled “Method of Forming Barbs on a Suture”, theentire disclosure of which is incorporated herein by reference. In theillustrative embodiment, the ultrasonic energy is generated by anapparatus 60 that includes a converter 62 which transmits ultrasonicenergy to a horn 66 that is operatively coupled to converter 62.Converter 62 converts electrical energy to mechanical energy whichcauses displacement of the tool at an ultrasonic frequency powered by anultrasonic generator or booster 68. Booster 68 may be manipulated toeither increase or decrease the ultrasonic frequency which may betransmitted to the tool. The ultrasonic frequency may range from about 1kHz to about 100 kHz. In other embodiments, the ultrasonic frequency mayrange from about 10 kHz to about 90 kHz. In still further embodiments,the ultrasonic frequency may range from about 15 kHz to about 50 kHz.The ultrasonic signal amplitude may range from about 1μ to about 125μ.In other embodiments, the signal amplitude may range from about 15μ toabout 60μ.

The ratio of the cut depth and the angle of the barbs relative to theelongated body of the medical device are variable based on the signalamplitude of ultrasonic energy applied to the cutting element. Forexample, as the ultrasonic amplitude is increased, the ratio of the cutdepth to the diameter and the angle of the barbs are decreased. As theultrasonic amplitude is decreased, the ratio of the cut is increased.

Referring back to FIG. 4A, in some embodiments, the compound barbs 12 asformed have a first angle α of approximately 0 degrees to about 90degrees, in embodiments, from 30 degrees to 50 degrees between compoundbarb 12 and elongated body 14 and a first ratio of cut depth which isapproximately 1% to about 40%, and in certain embodiments, about 10% toabout 30% of the diameter of the body.

Compound barb 12 as formed by the method of the present disclosure mayhave a second angle β of approximately 0 degrees to about 90 degrees, inembodiments, from 2 degrees to 25 degrees relative to the longitudinalaxis with a second ratio of cut depth of approximately 5% to about 50%,and in certain embodiments, about 15% to about 45% of the diameter ofelongated body 14. Compound barb 12 as formed by the method of thepresent disclosure may have a third angle γ of approximately 0 degreesto about 90 degrees, in embodiments, from about 25 degrees to about 50degrees relative to the longitudinal axis with a third ratio of cutdepth of approximately 15% to about 50%, and in some embodiments, fromabout 30% to about 50% the diameter of elongated body 14. In oneembodiment, a plurality of barbs are formed at successive intervalsalong the longitudinal axis of the medical device.

With continued reference to FIG. 9, the apparatus 60 optionally includesa gripper such as anvil 70 for supporting a medical device. The gripper70 supports the medical device at a fixed position. The horn 66 isconfigured and dimensioned to accept a cutting element such as a knifeblade or a rotary blade (not shown) for forming the barbs on the medicaldevice. The motorized slide 74 moves in an X, Y, and Z plane to allowthe medical device to pass in front of the converter to form barbsthereon. Apparatus 60 also includes rotational motor 76 which rotatesthe medical device in a circular direction. Advance slide 78 moves themedical device after every cut a specified increment for the appropriatebarb spacing. Apparatus 60 optionally includes camera 72 for recordingthe method of forming barbs and a light source 74 for optimizing theview of camera 72.

In embodiments, the medical device is moved to be contact with thecutting element, or in other embodiments, the medical device is movedagainst the cutting element, at a specified first angle relative to thelongitudinal axis of the elongated body of the medical device andforming a first ratio of cut depth to the diameter of approximately 1%to about 40%, in other embodiments more particularly a first ratio ofcut depth to the diameter of approximately 10% to about 30%. While thecutting element is still in contact with the medical device, a secondangle is cut having a ratio of cut depth to diameter of approximately 5%to about 50%, in other embodiments more particularly a ratio of cutdepth to diameter of approximately 15% to about 45%. Optionally, inother embodiments, while the cutting element is still in contact withthe medical device, a third angle is cut having a ratio of cut depth todiameter of approximately 15% to about 50%, in other embodiments moreparticularly a ratio of cut depth to diameter of approximately 30% toabout 50%. The amount of time the blade is in contact with the medicaldevice ranges, in embodiments, from about 1 millisecond to about 5seconds. In other embodiments, the amount of time the blade is incontact with the medical device ranges from about 1 second to about 3seconds. In still further embodiments, the amount of time the blade isin contact with the medical device is about 2 seconds.

In embodiments, the knife blade may be shaped substantially into arectangle shape, a square shape, a circle shape, a flat shape, anoctagonal shape, a triangle shape, a star shape, a spade shape, an arrowshape, a key shape and an elliptical shape. In some embodiments, thecurvature of the knife blade is substantially concave or substantiallyconvex.

In practice, the medical device passes in front of the converter 62which includes the horn 66 and the anvil 70, then using ultrasonicenergy at various frequencies and signal amplitudes cut the material toa geometry. In embodiments, the medical device passes in front ofconverter 62 via motorized slide 74 which is configured and dimensionedto hold gripper 70 and camera 72 thereon. In certain embodiments, themedical device passes in front of converter 62, via a mechanical feedingmechanism with the medical device held tightly around two spools on eachside of the apparatus (not shown). In other embodiments, the medicaldevice passes in front of converter 62 via human manipulation of themedical device.

Still referring to FIG. 9, the apparatus 60 includes a converter 62coupled to a horn 66 which operatively moves along a straight line X-Yplane via ultrasonic vibrational energy. The horn 66 includes a bladewhich contacts a surface of the medical device at an angle so as to format least one barb on the medical device. The blade is appropriatelypositioned to contact the medical device via knife positioning slide 80.After each barb is formed, the medical device is moved in a linearmotion on a X-Y plane via motorized slide 74 a specified length to allowanother barb to be formed thereon. In embodiments, the medical device ismoved in a X-Z plane via motorized slide 74 a specified length to form abarb thereon. In further embodiments, the medical device is moved in aY-Z plane via motorized slide 74 a specified length to form a barbthereon. In alternative embodiments, the medical device is moved in acircular manner via rotational motor 76 to form a barb at a specifiedposition. In embodiments, the medical device is moved in both arotational and x-z plane rotation.

In practice, the barbs 12 are formed as either the knife blade or rotaryblade (not shown) contacts the outer surface of the medical device. Theblade may be urged into contact with the surface of the medical device,for example, by a reciprocating actuator in a straight line X-Y plane.It is contemplated, however, that in alternative embodiments, the blademay be held fixed and the medical device may be urged toward the blade.The blade makes contact with the surface of the medical device at anangle relative thereto such that the combined action of the movement ofthe blade into contact with the medical device surface and theultrasonic vibration of the knife forms the desired barb. Advance slide78 then moves the medical device after every cut a specified incrementfor the desired spacing of the barbs.

Ultrasonic energy may transfer heat to the medical device as it isforming the barbs thereon. Depending on the amplitude, the ultrasonicfrequency may cause melting of medical device if the blades are left topenetrate medical device throughout the full wave cycle. To prevent thisfrom occurring, in some embodiments, the application of ultrasonicenergy is discontinued at some point prior to withdrawal of the bladesfrom contact of the medical device. In other embodiments, this methodmay be used to vary the angle and the depth of the cut as indicatedabove with respect to the increase or decrease of the amplitude.

In some embodiments, barbs may be formed by making acute angular cutsdirectly into the medical device body, with cut portions pushedoutwardly and separated from the body of the medical device. The depthof the barbs thus formed in the medical device body may depend on thediameter of the material and the depth of the cut.

In some embodiments, a suitable device for cutting a plurality ofaxially spaced barbs on the exterior of a filament may use a gripper asa cutting bed, a cutting bed vise, a cutting template, and a converterand horn as the blade assembly to perform the cutting. In operation, thecutting device has the ability to produce a plurality of axially spacedbarbs in the same or random configuration and at different angles inrelation to each other.

in other embodiments, the barbs may be arranged on a first portion of alength of the medical device body to allow movement of a first end ofthe medical device through tissue in one direction, while barbs on asecond portion of the length of the medical device body may be arrangedto allow movement of the second end of the medical device in an oppositedirection.

The barbs can be arranged in any suitable pattern, for example, helical,spiral, linear, or randomly spaced. The pattern may be symmetrical orasymmetrical. The number, configuration, spacing and surface area of thebarbs can vary depending upon the tissue in which the medical device isused, as well as the composition and geometry of the material utilizedto form the medical device. Additionally, the proportions of the barbsmay remain relatively constant while the overall length of the barbs andthe spacing of the barbs may be determined by the tissue beingconnected. For example, if the medical device is to be used to connectthe edges of a wound in skin or tendon, the barbs may be made relativelyshort and more rigid to facilitate entry into this rather firm tissue.Alternatively, if the medical device is intended for use in fattytissue, which is relatively soft, the barbs may be made longer andspaced further apart to increase the ability of the suture to grip thesoft tissue.

The surface area of the barbs can also vary. For example, fuller-tippedbarbs can be made of varying sizes designed for specific surgicalapplications. For joining fat and relatively soft tissues, larger barbsmay be desired, whereas smaller barbs may be more suitable forcollagen-dense tissues. In some embodiments, a combination of large andsmall barbs within the same structure may be beneficial, for examplewhen a suture is used in tissue repair with differing layer structures.In particular embodiments, a single directional suture may have bothlarge and small barbs; in other embodiments a bi-directional suture mayhave both large and small barbs.

Medical device 100 in accordance with the present disclosure may beformed of absorbable materials, non-absorbable materials, andcombinations thereof. More particularly, the medical device may beformed of an absorbable material selected from the group consisting ofpolyesters, polyorthoesters, polymer drugs, polydroxybutyrates,dioxanones, lactones, proteins, cat gut, collagens, carbonates,homopolymers thereof, copolymers thereof, and combinations thereof. Inother embodiments, suitable absorbable materials which may be utilizedto form the medical device include natural collagenous materials orsynthetic resins including those derived from alkylene carbonates suchas trimethylene carbonate, tetramethylene carbonate, and the like,caprolactone, glycolic acid, lactic acid, glycolide, lactide,homopolymers thereof, copolymers thereof, and combinations thereof. Insome embodiments, glycolide and lactide based polyesters, especiallycopolymers of glycolide and lactide, may be utilized to form the medicaldevice of the present disclosure.

Barbed medical devices fabricated from an absorbable material inaccordance with the present disclosure maintain their structuralintegrity after implantation (e.g., about 80% of original strength) fora period of time, depending on the various processing parameter and theparticular copolymer used. Such characteristics include, for example,the components of the copolymer, including both the monomers utilized toform the copolymer and any additives thereto, as well as the processingconditions (e.g., rate of copolymerization reaction, temperature forreaction, pressure, etc.), and any further treatment of the resultingcopolymers, i.e., coating, sterilization, etc.

The formation of barbs on a suture body may be utilized to alter thedegradation time of a suture in accordance with the present disclosureas described in U.S. patent application Ser. No. 11/556,002 filed onNov. 2, 2006 entitled “Long Term Bioabsorbable Barbed Sutures”, theentire contents of which are incorporated by reference herein.

For non-absorbable barbed medical devices constructed in accordance withthe present disclosure, suitable non-absorbable materials which may beutilized to form the medical device include polyolefins, such aspolyethylene, polypropylene, copolymers of polyethylene andpolypropylene, and blends of polyethylene and polypropylene; polyamides(such as nylon); polyamines, polyimines, polyesters such as polyethyleneterephthalate; fluoropolymers such as polytetrafluoroethylene;polyether-esters such as polybutesters; polytetramethylene ether glycol;1,4-butanediol; polyurethanes; and combinations thereof. In otherembodiments, non-absorbable materials may include silk, cotton, linen,carbon fibers, and the like. The polypropylene can be isotacticpolypropylene or a mixture of isotactic and syndiotactic or atacticpolypropylene.

The filaments and fibers used for forming the medical device of thepresent disclosure may be formed using any technique within the purviewof those skilled in the art, such as, for example, extrusion, moldingand/or solvent casting.

In one preferred embodiment, compound barbs are formed on a monofilamentsuture. A barbed monofilament suture may be preferred in embodimentswhere higher strength and longer absorption and strength profiles arepreferred. The compound barb monofilament sutures may be preferred, forexample, in dermal application where there is an increased risk ofinfection.

In some embodiments, devices of the present disclosure may include ayarn made of more than one filament, which may contain multiplefilaments of the same or different materials. Where the devices are madeof multiple filaments, the device can be made using any known techniquesuch as, for example, braiding, weaving or knitting. The filaments mayalso be combined to produce a non-woven suture. The filaments themselvesmay be drawn, oriented, crinkled, twisted, commingled or air entangledto form yarns as part of the suture forming process.

In other embodiments, compound barb medical devices may include othermedical devices such as braided sutures, surgical fibers, anchors, slitsheets, ribbons, tapes, meshes, stents, scaffolds, pledgets, andvascular grafts.

Once the medical device is barbed, it can be sterilized by any meanswithin the purview of those skilled in the art.

Medical devices in accordance with the present disclosure may be coatedor impregnated with one or more synthetic or natural polymers e.g.,bioactive agents which accelerate or beneficially modify the healingprocess when the suture is applied to a wound or surgical site. Incertain embodiments, the coating may be formed from absorbable polymersselected from the group consisting of lactones, carbonates,polyorthoesters, hydroxyalkoanates, hydroxybutyrates, bioactive agents,polyanhydrides, silicone, vinyl polymers, high molecular weight waxesand oils, natural polymers, proteins, polysaccharides, suspendableparticulates, dispersible particulates, microspheres, nanospheres, rods,homopolymers thereof, copolymers thereof, and combinations thereof.

Suitable bioactive agents include, for example, biocidal agents,antimicrobial agents, antibiotics, anti-proliferatives, medicants,growth factors, anti-clotting agents, clotting agents, analgesics,anesthetics, anti-inflammatory agents, wound repair agents and the like,chemotherapeutics, biologics, protein therapeutics, monoclonal orpolyclonal antibodies, DNA, RNA, peptides, polysaccharides, lectins,lipids, probiotics, diagnostic agents, angiogenics, anti-angiogenicdrugs, polymeric drugs, and combinations thereof.

Bioactive agents include substances which are beneficial to the animaland tend to promote the healing process. For example, a suture can beprovided with a bioactive agent that will be deposited at the suturedsite. The bioactive agent can be chosen for its antimicrobialproperties, capability for promoting wound repair and/or tissue growth,or for specific indications such as thrombosis. In embodiments,combinations of such agents may be applied to the medical device of thepresent disclosure after formation of the barbs.

The term “antimicrobial agent” as used herein includes an agent which byitself or through assisting the immune system, helps the body destroy orresist microorganisms which may be pathogenic. An antimicrobial agentincludes antibiotics, antiseptics, quorum sensing blockers, antifungals,anti-virals, surfactants, metal ions, antimicrobial proteins andpeptides, antimicrobial polysaccharides, disinfectants and combinationsthereof. Antimicrobial agents which are slowly released into the tissuecan be applied in this manner to aid in combating clinical andsub-clinical infections in a surgical or trauma wound site. Inembodiments, suitable antimicrobial agents may be soluble in one or moresolvents.

In embodiments, the following anti-microbial agents may be used alone orin combination with other bioactive agents described herein: ananthracycline, doxorubicin, mitoxantrone, a fluoropyrimidine,5-fluorouracil (5-FU), a folic acid antagonist, methotrexate,mitoxantrone, quorum sensing blocker, brominated or halogenatedfuranones, a podophylotoxin, etoposide, camptothecin, a hydroxyurea, aplatinum complex, cisplatin, doxycycline, metronidazole,trimethoprim-sulfamethoxazole, rifamycins like rifampin, a fourthgeneration penicillin (e.g., a ureidopenicillin a carboxypenicillin,meziocillin, piperacillin, carbenicillin, and ticarcillin, and ananalogue or derivative thereof), a first generation cephalosporin (e.g.,cephazolin sodium, cephalexin, cefazolin, cephapirin, and cephalothin),a carboxypenicillin (e.g., ticarcillin), a second generationcephalosporin (e.g., cefuroxime, cefotetan, and cefoxitin), a thirdgeneration cephalosporin (e.g., naxcel, cefdinir, cefoperazone,ceftazidime, ceftriaxone, and cefotaxime), polyvinyl pyrrolidone (PVP),a fourth generation cephalosporin (e.g., cefepime), a monobactam (e.g.,aztreonam), a carbapenem (e.g., imipenem, ertapenem and meropenem), anaminoglycoside (e.g., streptomycin, gentamicin, tobramycin, andamikacin), an MSL group member (e.g., a macrolide, a long actingmacrolide, a lincosamide, a streptogramin, Erythromycin, Azithromycin,Clindamycin, Syneroid, clarithromycin, and kanamycin sulfate),tetracyclines like minocycline, fusidic acid, trimethoprim,metronidazole; a quinolone (e.g., ciprofloxacin, ofloxacin,gatifloxacin, moxifloxacin, levofloxacin, and trovafloxacin), a DNAsynthesis inhibitor (e.g., metronidazole), a sulfonamide (e.g.sulfamethoxazole, trimethoprim, including cefixime, spectinomycin,tetracycline, nitrofurantoin, polymyxin B, and neomycin sulfate),beta-lactam inhibitors like sulbactam, chloramphenicol, glycopeptideslike vancomycin, mupirocin, polyenes like amphotericin B, azoles likefluconazole, and other known antimicrobial agent known in the art.

Examples of chemotherapeutics which may be utilized include one or moreof the following: doxorubicin (Dox), paclitaxel (PTX), or camptothecin(CPT), polyglutamate-PTX (CT-2103 or Xyotax),N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer, anthracycline,mitoxantrone, letrozole, anastrozole, epidermal growth factor receptorinhibitors, tyrosine kinase inhibitors, modulators of apoptosis,anthracycline antibiotics such as daunorubicin and doxorubicin,alkylating agents such as cyclophosphamide and melphalan,antimetabolites such as methotrexate and 5-fluorouracil, poly(ethyleneglycol) (PEG), poly(glutamic acid) (PGA), polysaccharides, monoclonalantibody and polymer-drug conjugates thereof, copolymers thereof andcombinations thereof.

The clotting agents include one or more of the following: a fibrosingagent that promotes cell regeneration, a fibrosing agent that promotesangiogenesis, a fibrosing agent that promotes fibroblast migration, afibrosing agent that promotes fibroblast proliferation, a fibrosingagent that promotes deposition of extracellular matrix, a fibrosingagent that promotes tissue remodeling, a fibrosing agent that is adiverticular wall irritant, silk (such as silkworm silk, spider silk,recombinant silk, raw silk, hydrolyzed silk, acid-treated silk, andacylated silk), talc, chitosan, bleomycin or an analogue or derivativethereof, connective tissue growth factor (CTGF), metallic beryllium oran oxide thereof, copper, saracin, silica, crystalline silicates, quartzdust, talcum powder, ethanol, a component of extracellular matrix,oxidized cellulose, polysaccharides, collagen, fibrin, fibrinogen,poly(ethylene terephthalate), poly(ethylene-co-vinylacetate),N-carboxybutylchitosan, an RGD protein, a polymer of vinyl chloride,cyanoacrylate, crosslinked poly(ethylene glycol)-methylated collagen, aninflammatory cytokine, TGFβ, PDGF, VEGF, TNFa, NGF, GM-CSF, IGF-a, IL-1,IL-8, IL-6, a growth hormone, a bone morphogenic protein, a cellproliferative agent, dexamethasone, isotretinoin, 17-β-estradiol,estradiol, diethylstibesterol, cyclosporine a, all-trans retinoic acidor an analogue or derivative thereof, wool (including animal wool, woodwool, and mineral wool), cotton, bFGF, polyurethane,polytetrafluoroethylene, activin, angiopoietin, insulin-like growthfactor (IGF), hepatocyte growth factor (HGF), a colony-stimulatingfactor (CSF), erythropoietin, an interferon, endothelin-1, angiotensinII, bromocriptine, methylsergide, fibrosin, fibrin, an adhesiveglycoprotein, proteoglycan, hyaluronan, secreted protein acidic and richin cysteine (SPaRC), a thrombospondin, tenacin, a cell adhesionmolecule, dextran based particles, an inhibitor of matrixmetalloproteinase, magainin, tissue or kidney plasminogen activator, atissue inhibitor of matrix metalloproteinase, carbon tetrachloride,thioacetamide, superoxide dismutase to scavenge tissue-damaging freeradicals, tumor necrosis factor for cancer therapy, colony stimulatingfactor, interferon, interleukin-2 or other lymphokines to enhance theimmune system, platelet rich plasma, thrombin, peptides such as selfassembly peptide systems, amino acids such as radA based amino acids,hydrogels such as super absorbing hydrogel materials, combinationsthereof, and so forth.

A wide variety of anti-angiogenic factors may be readily utilized withinthe context of the present disclosure. Representative examples includeAnti-Invasive Factor; retinoic acid and derivatives thereof; paclitaxela highly derivatized diterpenoid; Suramin; Tissue Inhibitor ofMetalloproteinase-1; Tissue Inhibitor of Metalloproteinase-2;Plasminogen Activator inhibitor-1; Plasminogen Activator Inhibitor-2;various forms of the lighter “d group” transition metals such as, forexample, vanadium, molybdenum, tungsten, titanium, niobium, and tantalumspecies and complexes thereof; Platelet Factor 4; Protamine Sulphate(Clupeine); Sulphated Chitin Derivatives (prepared from queen crabshells); Sulphated Polysaccharide Peptidoglycan Complex (SP-PG) (thefunction of this compound may be enhanced by the presence of steroidssuch as estrogen, and tamoxifen citrate); Staurosporine; Modulators ofMatrix Metabolism, including for example, proline analogs{[(L-azetidine-2-carboxylic acid (LACA), cishydroxyproline,d,L-3,4-dehydroproline, Thiaproline, α,α-dipyridyl, β-aminopropionitrilefumarate; MDL 27032 (4-propyl-5-(4-pyridinyl)-2(3H)-oxazolone;Methotrexate; Mitoxantrone; Heparin; Interferons; 2 Macroglobulin-serum;ChIMP-3; Chymostatin; β-Cyclodextrin Tetradecasulfate; Eponemycin;Camptothecin; Fumagillin Gold Sodium Thiomalate (“GST”); D-Penicillamine(“CDPT”); β-1-anticollagenase-serum; α2-antiplasmin; Bisantrene;Lobenzarit disodium (N-(2)-carboxyphenyl-4-chloroanthronilic aciddisodium or “CCA”; Thalidomide; Angostatic steroid; AGM-1470;carboxynaminolmidazole; metalloproteinase inhibitors such as BB94,analogues and derivatives thereof, and combinations thereof.

A wide variety of polymeric drugs may be readily utilized within thecontext of the present disclosure. Representative examples includesteroidal anti-inflammatory agents, non-steroidal anti-inflammatoryagents, and combinations thereof. Examples of the non-steroidalanti-inflammatory agent which may be used with the present disclosureare aspirin, indomethacin, ibuprofen, phenylbutazone, diflusinal, andcombinations thereof.

Examples of the steroidal anti-inflammatory agent which may be used areglucocorticoids such as cortisone and hydrocortisone, betamethasone,dexamethasone, fluprednisolone, prednisone, methylprednisolone,prednisolone, triamcinolone, paramethasone, and combinations thereof.

Although the above bioactive agents have been provided for the purposesof illustration, it should be understood that the present disclosure isnot so limited. In particular, although certain bioactive agents arespecifically referred to above, the present disclosure should beunderstood to include analogues, derivatives and conjugates of suchagents.

Medical devices in accordance with this disclosure can also include, forexample, biologically acceptable plasticizers, antioxidants andcolorants, which can be impregnated into the filament(s) utilized toform a suture of the present disclosure or included in a coatingthereon.

Bioactive agents may be applied onto a barbed medical device of thepresent disclosure utilizing any method within the purview of oneskilled in the art including, for example, dipping, spraying, vapordeposition, brushing, mixing, compounding and the like. In embodiments,a bioactive agent may be deposited within the barb angles, that is, theangle formed between the barb and the medical device surface inaccordance with the present disclosure as described in U.S. patentapplication Ser. No. 11/899,852 filed on Sep. 6, 2007 entitled“Bioactive Substance in a Barbed Suture”, the entire contents of whichare incorporated by reference herein.

Medical devices of the present disclosure may contain additives such asdyes, pigments, and colorants in order to increase the visibility of thedevice in the surgical field. Any suitable agent such as those agentswithin the purview of those skilled in the art can be used in accordancewith the present disclosure.

The filaments and sutures of the present disclosure may additionallyinclude a needle at one end. In order to facilitate needle attachment toa suture of the present disclosure, conventional tipping agents can beapplied to the braid. Two tipped ends of the suture may be desirable forattaching a needle to each end of the suture to provide a so-calleddouble armed suture. The needle attachment can be made by anyconventional method such as crimping, swaging, and the like.

In some cases, a tubular insertion device (not shown) may be utilized tointroduce a barbed medical device in accordance with the presentdisclosure into tissue. Such a tubular insertion device may have atubular body in which the barbed medical device of the presentdisclosure is disposed, as well as a distal end and a proximal end. Inuse, in some embodiments, the pointed end of a barbed suture of thepresent disclosure may be pushed with the distal end of the tubularinsertion device through skin, tissue, and the like at an insertionpoint. The pointed end of the suture and the distal end of the tubularinsertion device are pushed through the tissue until reaching anendpoint. The proximal end of the tubular insertion device is thengripped and pulled to remove the insertion device, leaving the barbedsuture in place.

Barbed sutures and placement methods suitable for use according to thepresent disclosure are well known in the art. For example, inembodiments, medical devices of the present disclosure may be utilizedto provide lift to tissue, which may be desirable in certain cosmeticapplications. In some embodiments, a procedure for closing tissueutilizing barbed sutures includes inserting a first end of amonofilament suture, optionally attached to a needle, at an insertionpoint through the body tissue. The first end of the suture may be pushedthrough body tissue until the first end extends out of the body tissueat an exit point. The first end of the monofilament suture may then begripped and pulled to draw the first portion of the suture through thebody tissue so that an outer surface of the elongate body (of the firstportion) of the suture remains in direct contact with the body tissuebetween the point of insertion and exit point of the first end. Asshown, for example in FIG. 10, the outer surface 630 of the elongatebody 610 is in direct contact with tissue “T.” The outer surface 630 maybe in direct contact with tissue “T” for any length “L” of the elongatebody and is not limited to the contact length “L” as shown in FIG. 10.The body tissue may then be manually grouped and advanced along at leastone portion of the monofilament suture to provide the desired amount oflift.

The medical devices of the present disclosure may be utilized in anycosmetic, endoscopic or laparoscopic methods. In addition, sutures ofthe present disclosure may be utilized to attach one tissue to anotherincluding, but not limited to, attaching tissue to a ligament. Specificapplications of cosmetic surgeries include, for example, facelifts,browlifts, thigh lifts, and breast lifts.

While the above description contains many specifics, these specificsshould not be construed as limitations on the scope of the disclosure,but merely as exemplifications of embodiments thereof. Those skilled inthe art will envision many other possibilities within the scope andspirit of the disclosure as defined by the claims appended hereto.

1-25. (canceled)
 26. A method of forming a compound barb on a medicaldevice, comprising the steps of: applying ultrasonic energy to a cuttingelement of a barb cutting apparatus; moving a medical device against thecutting element at a first angle relative to a longitudinal axis of themedical device to form a first cut in the medical device, the first cuthaving a first ratio of cut depth to diameter of the medical device;moving the medical device against the cutting element at a second anglerelative to a longitudinal axis of the medical device to form a secondcut in the medical device, the second cut having a second ratio of cutdepth to diameter of the medical device; and discontinuing theapplication of ultrasonic energy to the cutting element prior to movingthe medical device out of contact with the cutting element.
 27. Themethod according to claim 26, wherein moving the medical device againstthe cutting element at the first angle includes contacting the medicaldevice at the first angle of from about 0 degrees to about 90 degrees.28. The method according to claim 27, wherein contacting the medicaldevice at the first angle includes forming the first angle at about 30degrees to about 50 degrees.
 29. The method according to claim 28,wherein moving the medical device against the cutting element at thefirst angle includes cutting a surface of the medical device at thefirst ratio of cut depth to diameter of about 1% to about 40%.
 30. Themethod according to claim 27, wherein contacting the medical device atthe first angle includes forming the first angle at about 30 degrees toabout 40 degrees.
 31. The method according to claim 27, whereincontacting the medical device at the first angle includes forming thefirst angle at about 31 degrees to about 38 degrees.
 32. The methodaccording to claim 26, wherein moving the medical device against thecutting element at the second angle includes contacting the medicaldevice at the second angle of from about 0 degrees to about 90 degrees.33. The method according to claim 32, wherein contacting the medicaldevice at the second angle includes forming the second angle at fromabout 2 degrees to about 25 degrees.
 34. The method according to claim33, wherein moving the medical device against the cutting element at thesecond angle includes cutting a surface of the medical device at thesecond ratio of cut depth to diameter of about 5% to about 50%.
 35. Themethod according to claim 32, wherein contacting the medical device atthe second angle includes forming the second angle at from about 1degrees to about 10 degrees.
 36. The method according to claim 32,wherein contacting the medical device at the second angle includesforming the second angle at from about 1 degrees to about 8 degrees. 37.The method according to claim 26, wherein moving the medical deviceagainst the cutting element at the first and second angles includesforming the first angle such that it is greater than the second angle.38. The method according to claim 37, wherein moving the medical deviceagainst the cutting element at the first angle includes cutting asurface of the medical device at the first ratio of cut depth todiameter of about 1% to about 40%, and wherein moving the medical deviceagainst the cutting element at the second angle includes cutting thesurface of the medical device at the second ratio of cut depth todiameter of about 5% to about 50%.
 39. method according to claim 26,further comprising the step of increasing ultrasonic amplitude of theultrasonic energy to the cutting element after forming the first cut.40. The method according to claim 26, further comprising the step offorming the second cut while the cutting element is still in contactwith the medical device after forming the first cut.
 41. The methodaccording to claim 26, further comprising the steps of axially movingthe medical device a specified length after discontinuing theapplication of ultrasonic energy, and forming a barb thereon.
 42. Themethod according to claim 26, further comprising the step of selecting amedical device from the group consisting of monofilament sutures,braided sutures, multifilament sutures, surgical fibers, anchors, slitsheets, ribbons, tapes, meshes, stents, scaffolds, pledgets, andvascular grafts.